TDMA Based Collision Avoidance in Dense and Mobile RFID Reader Environment: DDFSA with RRE

摘要

Densely deployed mobile RFID readers are bound to have collisions and interference due to inherence limitations. In this paper, authors have addressed the reader to reader collision using modified similar frame slotted ALOHA technique, called Dynamic Demand-oriented Frame Slotted ALOHA (DDFSA) based on a deterministic approach to avoid the collision. The readers form discrete adhoc network autonomously and resources are distributed using the super frame. The frame size can dynamically change according to number of adjoining readers in the network. Readers can play a role of master, backup, participating or hanging node in the network. At the start of super frame resources are allocated. The redundant reader is eliminated using reader capability. The master disseminates the frame plan and resources. This improves the network throughput by reducing number of readers and utilizing all the times slots. The simulation tests results, using omnetpp+ software, show that resources are utilized up to 98 % with system efficiency at 99 % and nil unused time slots.